DESCRIPTION (taken directly from the application) This proposal is in response to RFA DK-94003, African American Study of Kidney Disease and Hypertension (AASK); Full Scale Trial. The applicants, Emory University and Morehouse School of Medicine, are collaborative participants in the current AASK Pilot Trial. Phase I (Jul 94 - Jun 96) is a 24-month period for recruitment of 65 African American patients with documented diastolic hypertension (HBP) and reduced renal function. These 65 patients will be randomized to one of three treatment arms: beta blocker, angiotensin converting enzyme inhibitor, or calcium channel blocker with assignment within each treatment group to two levels of control of mean arterial blood pressure (MAP): usual (MAP 102-107 mm Hg) and tight (MAP less than or equal to 92 rnm Hg). Phase 11 (Jul 96 - Jun 2000) is a 48-month period for intervention and patient follow-up with serial assessment of BP and renal function (125I-iothalamate GFR measurements). Phase 111 (Jul 2000 - Jun 2001) is a 12-month period for clinical center close-out, data analysis and reporting results. To accomplish the objectives of the RFA, Emory University and Morehouse School of Medicine offer a currently active team highly experienced in recruitment of minority participants into clinical trials, a staff trained in GFR techniques with precise timing of blood and urine specimens, and investigators with expertise in research on variables that influence progression of renal disease in hypertensive patients. The results will improve the understanding of the excess of hypertension- related end-stage renal disease in African Americans, and provide guidelines for appropriate antihypertensive drug therapy.